JPH072835B2 - Method for producing dialkoxy-bis (2-thienyl) silane polymer - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a conductivity and a redox property, and is useful as a conductive polymer material for various electric parts and electronic parts and as a redox electric element in the electrochemical field. The present invention relates to a method for producing an alkoxy-bis (2-thienyl) silane polymer.

[0002]

2. Description of the Related Art Conjugative polymers such as polyacetylene-based polymer compounds, polyphenylene-based polymer compounds, polypyrrole-based polymer compounds, polythiophene-based polymer compounds and polyselenophene-based polymer compounds have hitherto been used as conductive polymer compounds. In the form of electron transfer through a double bond,
Polymers such as polyacene-based polymer compounds, polyperinaphthalene-based polymer compounds that transfer electrons through condensed aromatic rings, and ionized atoms such as polyaniline and poly (3-methyl-4-carboxypyrrole) It is known that electron transfer is performed through atomic groups, but most of them are insoluble and infusible, so they lack workability and are inferior in mechanical properties. ,
The range of use is unavoidable.

Therefore, it has been a major problem in this field to develop a conductive polymer compound having a novel structure and to expand the field of application according to its physical properties.

By the way, recently, a conductive polymer compound having a structure in which a heterocycle is linked via a silicon atom has been studied, and so far, a general formula has been used.

[Chemical 3] (Wherein R is a methyl group, a phenyl group or a p-tolyl group) having a repeating unit [“Macromolecules”
s) ", Vol. 24, No. 8, pp. 2106-2107 (1991)] and general formula

[Chemical 4] (X in the formula is S, O, Se or Te, and R and R '
Is a hydrogen atom, an alkyl group or an aryl group), and is a polymer of a compound represented by JP-A-3-76714.
However, all of them are difficult to put into practical use because they lack workability.

[0005]

SUMMARY OF THE INVENTION The present invention has been made for the purpose of providing a method for easily producing a conductive polymer compound having excellent conductivity and heat resistance.

[0006]

By the way, conductive polymer compounds are mainly produced by electrolytic polymerization,
This method uses electrolytes such as special aprotic polar solvents,
In addition to device problems that require electrodes such as platinum and other noble metals such as anodes, there are work problems such as strict setting of processing conditions such as current density and reaction temperature. Was inappropriate.

The inventors of the present invention have conducted various studies on a method for producing a conductive polymer compound having a structure in which thiophene rings are linked via a silicon atom, more easily.
Previously, a method for producing a dialkoxy-bis (2-thienyl) silane polymer by electrolytic polymerization of dialkoxy-bis (2-thienyl) silane was developed. By treating bis (2-thienyl) silane with iron (III) chloride,
It was found that poly [dialkoxy-bis (2-thienyl) silane] can be obtained by polymerizing as it is without any change in its basic structure, and the present invention has been completed based on this finding.

That is, the present invention has the general formula (I)

[Chemical 5] A general formula, characterized in that a dialkoxy-bis (2-thienyl) silane represented by the formula (wherein R ¹ and R ² are alkyl groups) is contacted with iron (III) chloride.

[Chemical 6] The present invention provides a method for producing a dialkoxy-bis (2-thienyl) silane polymer composed of repeating units represented by the formula (R ¹ and R ² are alkyl groups).

In the compound of the general formula (I) used as a raw material in the method of the present invention, R ¹ and R ² may be the same or different from each other, and each has 1 to 1 carbon atoms.
A straight chain or branched alkyl group of 8 is preferred. Examples of such an alkyl group include a methyl group, an ethyl group,
Examples thereof include propyl group, isopropyl group, butyl group, isobutyl group, pentyl group, hexyl group, heptyl group and octyl group.

Examples of such raw material compounds include diethoxybis (2-thienyl) silane and dimethoxybis (2-
Thienyl) silane, dipropoxybis (2-thienyl)
Silane, dibutoxybis (2-thienyl) silane, dipentyloxybis (2-thienyl) silane, dihexyloxybis (2-thienyl) silane, dioctyloxybis (2-thienyl) silane, methoxyethoxybis (2-thienyl) silane, Methoxypropoxybis (2
-Thienyl) silane, methoxybutoxybis (2-thienyl) silane, ethoxypropoxybis (2-thienyl) silane, ethoxybutoxybis (2-thienyl) silane, methoxypentyloxybis (2-thienyl) silane, methoxyhexyloxybis Examples include (2-thienyl) silane, methoxyoctyloxybis (2-thienyl) silane, and propoxybutoxybis (2-thienyl) silane.

The starting compound dialkoxy-bis (2-thienyl) silane is obtained by reacting a thiophene substituted at the 2-position with an alkali metal such as 2-lithiothiophene and dihalodialkoxysilane in a molar ratio of 2: 1. Can be obtained by

This reaction is carried out under an inert atmosphere in an inert solvent at 0 ° C. or lower, preferably − in order to suppress side reactions.
Preference is given to carrying out at temperatures between 10 and -40 ° C. Nitrogen, argon, etc. are used as the inert atmosphere at this time. In addition, examples of the inert solvent include ethers such as diethyl ether, methyl ethyl ether, dipropyl ether and tetrahydrofuran, and liquid hydrocarbons such as hexane, pentane and cyclohexane.

To carry out this method, the dialkoxy-bis (2-thienyl) silane of the above general formula (I) is dissolved in an inert solvent, and iron (III) chloride powder is added thereto,
It is advantageous to stir. The reaction temperature in this case is in the range of 0 ° C to 100 ° C, but room temperature or a slightly heated temperature is preferable. This reaction is completed in about 30 minutes to 2 hours, so the reaction mixture obtained is poured into a non-solvent such as methanol, and the precipitate is filtered off to obtain the desired dialkoxy-bis (2-thienyl) silane. The coalescence is obtained as a red powder.

The conductive polymer obtained by the method of the present invention has the general formula

[Chemical 7] It is composed of a repeating unit represented by the formula (R ¹ and R ² in the formula are alkyl groups) and does not dissolve in a solvent. Therefore, its molecular weight cannot be accurately measured. It is estimated that the molecular weight of the coalesced product and its polymerization conditions are in the range of about 1,000 to 100,000.

[0015]

EXAMPLES Next, the present invention will be described in more detail by way of examples.

Reference Example To a mixture of 5.05 g (60.0 mmol) of thiophene and 50 ml of diethyl ether, a hexane solution of 60.0 mmol of n-butyllithium was added dropwise at -40 ° C. under a nitrogen atmosphere, and a dry ice-acetone refrigerant was used. Stir at -40 ° C for 2 hours. A solution of 5.67 g (30.0 mmol) of dichlorodiethoxysilane dissolved in 5 ml of diethyl ether was added dropwise thereto at -20 ° C, and the mixture was stirred at room temperature for 12 hours. After neutralizing the reaction mixture with 4N hydrochloric acid,
This was put into 200 ml of ice water, and a colorless oily substance was obtained from the ether extract by a conventional method. This was further purified by silica gel column chromatography (Wako Gel C-200), and 5.31 g of diethoxybis (2-thienyl) silane as a colorless oil was obtained from the hexane eluate (yield 62.0).
%) Was obtained. The identification data for this item are as follows.

¹ H-NMR (CDCl ₃ , δ): 1.27
(T, J = 10.6 Hz, 6H), 3.93 (g, J =
6.9 Hz, 4H), 7.22 (dd, J = 3.4H)
z, J = 4.6 Hz, 2H), 7.48 (dd, J =
1.0 Hz, J = 3.4 Hz, 2H), 7.68 (d
d, J = 1.0 Hz, J = 4.6 Hz, 2H) ¹³ C-NMR (CDCl ₃ , δ): 18.2, 59.
4, 128.2, 132.4, 137.3 IR (KBr, ν, cm ^-1 ): 3102 (w), 297.
4 (m), 1406 (m), 1215 (m), 1166
(M), 1078 (s), 1008 (m), 962
(M), 785 (m), 713 (s), 528 (m)

Examples Diethoxybis (2-thienyl) silane 1 obtained in Reference Example
10m of chloroform containing 42mg (0.5mmol)
324 mg (2.0 mmo) of iron (III) chloride
l) was added and the mixture was stirred at 30 ° C. for 1 hour in a nitrogen atmosphere.
Next, the obtained reaction mixture was put into 30 ml of methanol, and the generated precipitate was separated by filtration. The filtered material was thoroughly washed with methanol and then with a methanol solution of hydrazine, and then dried under reduced pressure to obtain 22 mg of a red powder.

Infrared absorption analysis of the red powder thus obtained revealed that absorption at 1,078 cm ^{-1 due} to stretching of Si-O and absorption at 785 cm ^-1 of disubstituted thiophene ring C-H.
Absorption due to out-of-plane bending vibration was observed at high strength. From this, this red powder was identified as a polymer of diethoxybis (2-thienyl) silane.

Next, 200 kg / cm ^{2 of} this red powder was added.
It is compressed and molded into pellets under the pressure of
When I ₂ was doped and the electrical conductivity was measured by the four-terminal method, the electrical conductivity was 2.1 × 10 ⁻¹ S · cm ⁻¹ .

[0021]

EFFECTS OF THE INVENTION According to the method of the present invention, a conductive polymer exhibiting high electric conductivity and capable of redox can be obtained by a simple operation. The conductive polymer obtained by the method of the present invention can be suitably used as a conductive material for various electric parts and electronic parts, and an electric element in the field of electrochemistry.

Claims (1)

[Claims] 1. A general formula: A general formula characterized in that a dialkoxy-bis (2-thienyl) silane represented by the formula: wherein R ¹ and R ² are alkyl groups is contacted with iron (III) chloride. A method for producing a dialkoxy-bis (2-thienyl) silane polymer composed of repeating units represented by the formula (R ¹ and R ² are alkyl groups).